As a owner of mc452, I dont think a powercord will do so much to an amp. I have no idea why people could hear so many different things from copper /silver what the cable is made of. I can sell you my nrg2 if its not too cheap to you. I bought it because it looks better than the standard cord.
Power Cables
I am currently upgrading my system. I had a pair of XLO Ultra speaker cables sitting around and was very impressed with the improvement over the original Monster cable. Having come back from Axpona, I am wondering what fellow Audiogon members would recommend for a power cable with tight bass, superb mids and extended highs that would help to produce a very full, wide and deep soundstage. I am looking to replace the cable on my Adcom GFA-5802. I do agree with philosophy of starting with the power. I have demoed one other power cable and the difference is immense. Thanks in advance for the advice.